研究:電流刺激大腦可增強學習能力
Electrically stimulating the brain can help to speed up the process of learning, scientists have shown。
Applying a small current to specific parts of the brain can increase its activity, making learning easier。
Researchers from the University of Oxford have studied the changing structure of the brain in stroke patients and in healthy adults。
Prof Heidi Johansen-Berg presented their findings at the British Science Festival in Bradford。
The team at Oxford has been conducting research into how the structure of the brain changes in adulthood, and in particular what changes occur after a stroke。
They have used an approach called functional MRI to monitor activity in the brain as stroke patients re-learn motor skills that were lost as a result of their illness。
One of the major findings is that the brain is very flexible and can restructure itself, growing new connections and reassigning tasks to different areas, when damage occurs or a specific task is practised。
As part of this research, they investigated the possibility of using non-invasive electric brain stimulation to improve the recovery of these motor skills; the short-term improvement in stroke patients had already been noted。
But an unexpected result was found when the same brain stimulation was applied to healthy adults: their speed of learning was also significantly increased。
To observe this effect, the team devised an experiment whereby volunteers memorised a sequence of buttons to press "like playing a tune on a piano"。
While they were doing this, they were fitted with a "trans-cranial current stimulation" device, in which two electrodes are placed in a specific position on the head。
A very small current was passed between the electrodes in an arc through the brain and, depending on the direction of that current, either increased or decreased the activity of that part of the brain。
Prof Johansen-Berg explained that "an increase in activity of the brain cells makes them more susceptible to the kinds of changes that occur during learning"。
The results of the button-pressing experiments showed the positive effects of just 10 minutes of the brain stimulation on learning。
"While the stimulation didn't improve the participant's best performance, the speed at which they reached their best was significantly increased." said Prof Johansen-Berg。
In the treatment of stroke patients, the technique could be used in parallel with current physiotherapy treatments to improve overall outcomes, which tend to vary widely。據英國廣播公司9月20日報道，近期科學家研究指出，電流刺激大腦能夠加速認知學習的過程。
用較小的電流刺激大腦的特定部位，可使該部位更加活躍，學習更輕鬆。
來自牛津大學的研究者研究了中風病人與健康成人大腦結構的變化。
在布拉德福德舉辦的英國科學節上，海蒂·約翰森伯格教授介紹了他們這一研究結果。
牛津研究小組一直在研究成年後大腦的結構變化，特別是中風後又發生了怎樣的變化。
中風患者因爲疾病原因已經忘記了原有運動技能。研究者們使用功能性磁核共振成像的方法，監測了他們重新學習該技能時的大腦活動。
主要發現之一是，其大腦非常靈活並可以自行調整腦結構，在遇到損毀或特殊任務時能產生、新的連接，並重新分配了不同腦部位的任務。
作爲這項研究的一部分，他們調查了使用非侵入性的電流對腦部刺激以改善其運動技能的恢復的可能性，中風患者中有短期改善已被標記。
一個意想不到的結果是，健康的成年人受到相同的大腦刺激時，他們的學習速度也顯著增加。
爲了觀察這種效果，研究者們設計了一個實驗，讓志願被試者像在鋼琴上演奏曲子一樣來按一串按鈕。
當他們這樣做，他們實際上按住了“跨顱電流刺激”的裝置，它的兩個電極放置在頂端的特定位置。
電極之間傳遞的小股電流呈弧狀通過大腦，電流的方向即可增加或減少的那部分大腦的活動。
約翰森伯格教授解釋說，“增加腦細胞的活動使大腦更易受學習過程發生的變化的影響”。
按鈕實驗結果顯示，僅10分鐘的腦刺激即可對學習產生的積極影響。
“雖然刺激沒能使參與者的表現提高到最佳，但達到他們最佳表現的速度顯著增加。”約翰森伯格教授說。
在對中風患者的治療中，該技術可以與目前的物理療法並行來明顯提高整體療效。
